Known devices for toilet ventilation suffer from the disadvantages and costs of having air conduits that are routed outside the toilet bowl and plumbed into the septic line intrusively, or otherwise require substantial modifications to the design of a conventional toilet. Still other devices have separate air manifolds that fit underneath the toilet, which are costly and require significant effort to install. Also, mechanical or pneumatic valves are frequently used with known devices to prevent the backflow of septic odors into the toilet bowl. The present invention provides a ventilation device which is readily adaptable to an existing toilet. Furthermore, some of the distinct benefits of the invention can be realized by “original equipment manufacturer” (OEM) toilets that incorporate the invention, as-purchased. Furthermore, a valve to control the backflow of septic odors is not required.